JP2010234813A - Decorative sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently provide a decorative sheet which has excellent repelling performance (pollution resistance) and durability. <P>SOLUTION: In the decorative sheet to be used by being laminated on an adhered material, (1) the sheet sequentially has at least a base material sheet, a design layer, a transparent resin layer and a surface protective layer, (2) the surface protective layer is formed of a composition including (a) an ionizing radiation polymerizable oligomer, and (b) a reactive silicone acrylate, (3) the ionizing radiation polymerizable oligomer is a mixture which is formed of (A) 40 to 80 wt.% of an urethane (meth)acrylate oligomer having at least two radical polymerizable unsaturated groups, and (B) 60 to 20 wt.% of an aliphatic urethane(meth)acrylate oligomer having 3 to 15 radical polymerizable unsaturated groups in one molecule. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a decorative sheet provided with an effective pattern as a surface decoration material for building materials such as furniture and joinery, and a decorative board on which the decorative sheet is laminated.

  The decorative sheet is used for the purpose of protecting the surface of an adherend such as a wooden board, decoration, and the like, and is used by sticking it on the surface of the adherend. And the decorative board obtained by this is used for various building materials, furniture, etc.

  The decorative sheet is provided with a surface protective layer to protect the outermost surface. Therefore, the surface protective layer needs to be excellent in wear resistance, scratch resistance, and the like. In addition, the surface protective layer needs to have stain resistance (antifouling property) against dirt from the outside.

  As cosmetics excellent in wear resistance, stain resistance, etc., for example, a layer (2) containing a colorant, a synthetic resin layer (3), and the synthetic resin layer (3) on one side of the base film (1). A decorative sheet characterized in that a synthetic resin layer (4) different from) is laminated in this order has been proposed (Patent Document 1).

  Further, in the antifouling cosmetic material in which the antifouling layer is provided on the base material, the antifouling layer is made of a silicone-modified acrylic urethane resin in which an organopolysiloxy group is introduced into a side chain of the acrylic urethane resin. A characteristic antifouling cosmetic material has also been proposed (Patent Document 2).

JP-A-11-58614 JP 2004-17617 A

  However, in the decorative sheet of Patent Document 1, a silicone resin, a fluororesin, or the like having a low surface tension is used as the outermost synthetic resin layer. For this reason, there is a problem in terms of durability and the like.

  In general, the decorative sheet is stored in a roll shape or in a laminated state. At this time, if a large amount of the silicone resin is bleed on the surface of the decorative sheet, it tends to adhere to the back surface of one of the decorative sheets. Even in Patent Document 1, a relatively large amount of silicone resin may bleed. When the back surface of the decorative sheet is soiled with a silicone resin, there is a possibility that predetermined adhesiveness may not be obtained when the decorative sheet is attached to a plywood or the like.

  In the decorative sheet of Patent Document 2, a silicone-modified resin is used as an antifouling layer, and the silicone-modified resin is bleeded on the surface of the decorative sheet to obtain stain resistance (particularly resistance to dirt due to writing instruments, dirt due to food, etc.). Is. Therefore, similarly to Patent Document 1, a problem due to bleeding of the silicone-modified resin occurs.

  Moreover, in patent document 2, since the silicone modified resin which has formed the antifouling layer on the surface is wiped off at the same time by wiping off the decorative sheet, it is difficult to maintain the stain resistance for a long period of time. become.

  Accordingly, a main object of the present invention is to efficiently provide a decorative sheet having excellent repellency (contamination resistance) and durability.

  In light of the problems of the prior art, the present inventor has found that the above object can be achieved by using a laminate having a specific configuration as a decorative sheet as a result of intensive studies, and has completed the present invention. .

  That is, the present invention relates to the following decorative sheet.

1. A decorative sheet for use by laminating on an adherend,
(1) The sheet has at least a base sheet, a pattern layer, a transparent resin layer, and a surface protective layer in order,
(2) The surface protective layer is formed of a composition comprising a) an ionizing radiation polymerizable oligomer and b) a both-end reactive silicone acrylate,
(3) The ionizing radiation polymerizable oligomer includes (A) 40 to 80% by weight of a urethane (meth) acrylate oligomer having two radical polymerizable unsaturated groups in one molecule and (B) 3 to 3 in one molecule. It is a mixture comprising 60 to 20% by weight of an aliphatic urethane (meth) acrylate oligomer having 15 radically polymerizable unsaturated groups.
A decorative sheet characterized by that.

  2. Item 2. The decorative sheet according to Item 1, wherein at least a primer layer is formed between the transparent resin layer and the surface protective layer.

  3. Item 3. The decorative sheet according to Item 1 or 2, wherein the surface protective layer contains a matting agent.

  4). Item 4. The decorative sheet according to Item 3, wherein a part or all of the matting agent is silica particles.

  5. Item 5. The decorative sheet according to Item 3 or 4, wherein the matting agent contains untreated silica particles.

6). The decorative sheet according to any one of Items 3 to 5, wherein silica having an apparent specific gravity of 0.05 to 0.4 g / cm ³ or 0.45 to 1.0 g / cm ³ is used in combination as the matting agent.

  7). Item 7. The decorative sheet according to any one of Items 1 to 6, wherein the surface protective layer has unevenness by embossing.

  8). Item 8. The decorative sheet according to any one of Items 1 to 7, wherein at least one of the transparent resin layer and the base sheet is a polyolefin-based resin.

  9. The decorative board formed by laminating | stacking the said sheet | seat on a to-be-adhered material so that the surface protection layer of the decorative sheet in any one of said item | item 1-8 may become an outermost surface layer.

  According to the decorative sheet of the present invention, since the surface protective layer is formed of a composition containing an ionizing radiation polymerizable oligomer and a reactive silicone acrylate, excellent repellency (contamination resistance) while avoiding the problem of bleeding. Property) and durability.

  That is, the decorative sheet of the present invention has excellent surface resistance and durability over a long period of time because the surface protective layer is particularly resistant to contamination (so-called excellent repellency) and has a sustained effect. be able to.

  In addition, the decorative sheet of the present invention can exhibit more excellent surface design properties (particularly various gloss levels) when a matting agent is used.

The decorative sheet of the present invention is a decorative sheet for use by being laminated on an adherend,
(1) The sheet has at least a base sheet, a pattern layer, a transparent resin layer, and a surface protective layer in order,
(2) The surface protective layer is formed of a composition comprising a) an ionizing radiation polymerizable oligomer and b) a reactive silicone acrylate,
(3) The ionizing radiation polymerizable oligomer includes (A) 40 to 80% by weight of urethane (meth) acrylate oligomer having at least two radical polymerizable unsaturated groups in one molecule and (B) 3 in one molecule. It is a mixture comprising 60 to 20% by weight of an aliphatic urethane (meth) acrylate oligomer having -15 radical polymerizable unsaturated groups,
It is characterized by that. Hereinafter, each layer will be described.

As the base sheet , for example, paper, non-woven fabric, thermoplastic resin sheet, or a composite material thereof is used.

  Examples of the paper include thin paper, kraft paper, high quality paper, linter paper, baryta paper, sulfate paper, and Japanese paper.

Moreover, as a nonwoven fabric, the nonwoven fabric which consists of fibers, such as a polyester resin, an acrylic resin, nylon, vinylon, glass, is mentioned, for example. The basis weight of the paper or non-woven fabric is usually about ²⁰ to 100 g / m ² . In addition, for paper or non-woven fabric, resin such as acrylic resin, styrene butadiene rubber, melamine resin, urethane resin is added to strengthen the interlaminar strength between the fibers and other layers, and to prevent galling. It may be impregnated with resin or embedded during papermaking. Note that a decorative sheet using paper (or non-woven fabric) as a base sheet is decorative paper.

  Examples of the thermoplastic resin sheet include acrylic resin, polyester resin, polyolefin resin, polyvinyl chloride resin, polystyrene, ABS resin, polycarbonate resin, and polyamide resin. More specifically, the following (1) to (4) may be mentioned.

(1) Polyethylene (high density, medium density or low density), polypropylene (isotactic or syndiotactic), polybutene, ethylene-propylene copolymer, ethylene-propylene-butene copolymer, olefin Polyolefin resins such as thermoplastic elastomers The olefin thermoplastic elastomers include hard segments composed of crystalline polyolefin resins as exemplified above, ethylene-propylene rubber, ethylene-propylene-diene rubber, atactic polypropylene, styrene- A soft segment made of an elastomer such as butadiene rubber or hydrogenated styrene-butadiene rubber is mixed. The mixing ratio of the hard segment and the soft segment is about [soft segment / hard segment] = 5/95 to 40/60 (mass ratio). If necessary, the elastomer component is crosslinked by a known crosslinking agent such as sulfur or hydrogen peroxide.

  (2) Acrylic resins such as polymethyl (meth) acrylate, polybutyl (meth) acrylate, methyl (meth) acrylate-butyl (meth) acrylate copolymer, methyl (meth) acrylate-styrene copolymer [however, (meth) Acrylate means acrylate or methacrylate].

(3) Polyester resin such as polyethylene terephthalate, polybutylene terephthalate, ethylene-terephthalate-isophthalate copolymer, polyethylene naphthalate, polyester-based thermoplastic elastomer, amorphous polyester, etc. The segment has a high crystalline and high melting point aromatic polyester, and the soft segment has a block polymer using amorphous polyether having a glass transition temperature of −70 ° C. or less. For example, polybutylene terephthalate is used as the polyester, and polytetramethylene glycol or the like is used as the amorphous polyether. The amorphous polyester typically includes ethylene glycol-1,4-cyclohexanedimethanol-terephthalic acid copolymer.

(4) Other resins For example, polycarbonate resin, polyvinyl chloride resin, polyamide resin, polyphenylene sulfide, polyether ether ketone and the like can be mentioned.

  As a layer structure of the base sheet, the above-mentioned paper, non-woven fabric, thermoplastic resin sheet and the like can be used by laminating them in a single layer or two or more layers.

  Although the thickness (total thickness in the case of a laminated body) of a base material sheet is not limited, Generally, What is necessary is just to be about 25-500 micrometers.

Pattern layer The pattern layer can represent not only patterns of natural materials such as wood grain and joints, but also letters, symbols, drawings, and the like.

  In the case of providing a pattern layer, the pattern layer forming method, material, pattern type, and the like are not particularly limited. The pattern layer is usually formed using ink and can be formed by a known printing method such as gravure printing, silk screen printing, offset printing, gravure offset printing, and ink jet printing. As the picture pattern, for example, a grain pattern, a stone pattern, a grain pattern, a cloth pattern, a tile-like pattern, a brick-like pattern, a leather pattern, a character, a symbol, a geometric pattern, or a combination of two or more of these can be adopted.

  The ink used for forming the pattern layer is 1) a vehicle composed of a binder, 2) a colorant such as a pigment or dye, 3) an extender pigment, a stabilizer, a plasticizer, a catalyst, a curing agent, etc. Consists of various additives.

  The binder resin may be appropriately selected from known binders such as a thermoplastic resin, a thermosetting resin, and an ionizing radiation curable resin according to required physical properties, printability, and the like. For example, cellulose resins such as nitrocellulose, cellulose acetate, cellulose acetate propionate; poly (meth) methyl acrylate, poly (meth) butyl acrylate, methyl (meth) acrylate-butyl (meth) acrylate- ( In addition to an acrylic resin such as a (meth) acrylic acid 2-hydroxyethyl copolymer, a simple substance such as urethane resin, vinyl chloride-vinyl acetate copolymer, polyester resin, alkyd resin, or a mixture containing these can be used.

  In addition, as coloring agents, inorganic pigments such as titanium white, carbon black, iron black, petal, yellow lead and ultramarine, organic pigments such as aniline black, quinacridone red, isoindolinone yellow and phthalocyanine blue, titanium dioxide coated mica In addition to bright pigments such as foil powder such as aluminum, various dyes can be used.

Adhesive Layer In the decorative sheet of the present invention, an adhesive layer is preferably interposed between the picture layer and the transparent resin layer.

  The adhesive used in the adhesive layer can be appropriately selected from known or commercially available adhesives according to the components constituting the pattern layer or the transparent resin layer. Examples thereof include thermosetting resins such as polyester resins, polyurethane resins, and epoxy resins, in addition to polyolefin resins such as polyethylene and polypropylene.

  Among these, in this invention, a urethane type resin adhesive is preferable at the point that heat resistance etc. can be improved more. Examples of the urethane resin adhesive include a two-component curable urethane resin having a polyol as a main component and an isocyanate as a crosslinking agent (curing agent).

  The polyol has two or more hydroxyl groups in the molecule. For example, polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol, polycarbonate polyol and the like are used.

  Moreover, as said isocyanate, the polyvalent isocyanate which has a 2 or more isocyanate group in a molecule | numerator is used. For example, aromatic isocyanates such as 2,4-tolylene diisocyanate, xylene diisocyanate, 4,4-diphenylmethane diisocyanate, aliphatics such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate (or Alicyclic) isocyanates are used. Further, adducts or multimers of the above various isocyanates can also be used. Examples thereof include adducts of tolylene diisocyanate and trimers of tolylene diisocyanate.

  If necessary, the adhesion surface can be subjected to known easy adhesion treatment such as corona discharge treatment, plasma treatment, degreasing treatment, and surface roughening treatment.

  What is necessary is just to implement as an adhesion | attachment method according to a well-known method according to the kind etc. of adhesive agent to be used. For example, using a polyolefin resin such as polyethylene or polypropylene, a method of coating on a pattern layer by melt extrusion (extrusion coating method), a thermosetting resin such as a polyester resin, a polyurethane resin, or an epoxy resin, isocyanate, Apply an adhesive such as a crosslinking agent such as amine, a polymerization initiator such as methyl ethyl ketone peroxide, hydroperoxide, azabisisobutyronitrile, a polymerization accelerator such as cobalt naphthenate, dimethylaniline, etc. A dry laminating method can be employed. In the present invention, an adhesive capable of thermocompression bonding is used, and the pattern layer and the transparent resin layer can be laminated by thermocompression bonding.

  In the present invention, a known easy adhesion treatment such as a corona discharge treatment, a plasma treatment, a degreasing treatment, a surface roughening treatment or the like can be applied to the adhesion surface as necessary.

  The thickness of the adhesive layer varies depending on the type of the transparent protective layer, the type of adhesive to be used, and the like, but is usually about 0.1 to 30 μm.

Transparent resin layer The transparent resin layer is not limited as long as it is transparent. Accordingly, it includes any of colorless and transparent, colored and transparent, translucent and the like.

  As a transparent resin layer, what was formed, for example with the thermoplastic resin can be used conveniently. Specifically, soft, semi-rigid or rigid polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyethylene, polypropylene, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid ester copolymer Polymers, ionomers, acrylic esters, methacrylic esters and the like can be mentioned. In the present invention, a polyolefin resin such as polypropylene is particularly preferable as the transparent resin layer.

  The transparent resin layer may be colored as necessary. In this case, a coloring material (pigment or dye) can be added to the above thermoplastic resin for coloring. As the colorant, a known or commercially available pigment or dye can be appropriately used. These can select 1 type, or 2 or more types. Further, the addition amount of the colorant may be appropriately set according to the desired color tone.

  For the transparent resin layer, a filler, a matting agent, a foaming agent, a flame retardant, a lubricant, an antistatic agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a radical scavenger, a soft component (as necessary) For example, various additives such as rubber) may be included.

  A flame retardant is added in order to provide flame resistance. For example, chlorinated paraffin, tricresyl phosphate, chlorinated oil, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, tetrabromobisphenol A, dibromopropyl phosphate, tri (2,3-dibromopropyl) phosphate, antimony oxide, hydrous alumina Barium borate and the like can be preferably used.

  Antioxidants are added to suppress or prevent oxidative degradation. For example, alkylphenols, amines, quinones and the like are suitable.

  It absorbs ultraviolet rays in a wavelength range of 280 to 450 nm, which causes deterioration of ultraviolet absorbers and resins (particularly polyolefin resins). Examples thereof include benzophenone-based, salicylate-based, benzotriazole-based, and acrylonitrile-based ultraviolet absorbers.

  The radical scavenger is added to prevent discoloration due to sunlight, cracks, whitening, strength deterioration and the like and improve weather resistance. As the radical scavenger, in addition to bis- (2,2,6,6-tetramethyl-4-piperidinyl) sebacate, for example, a hindered amine radical scavenger such as a compound disclosed in JP-B-4-82625, Piperidyl radical scavengers and the like are used.

  The forming method of the transparent resin layer is not limited, for example, a method of laminating a preformed sheet or film on an adjacent layer, an adjacent layer by melt-extruding a resin composition capable of forming a transparent resin layer Any of a method of coating on top and a method of laminating together with an adjacent layer can be employed. In the present invention, it is particularly preferable to form the transparent resin layer by melt extrusion. In particular, the transparent resin layer is preferably applied by melt extrusion of a polyolefin resin. Specifically, the transparent resin layer can be suitably formed by forming an adhesive layer on the pattern layer in advance, and melt-extruding and applying a polypropylene-based thermoplastic elastomer onto the adhesive layer. What is necessary is just to implement the method of melt extrusion according to the well-known method using a T die etc., for example.

  The thickness of the transparent resin layer can be appropriately set depending on the use of the final product, the method of use, etc., but it is generally preferably 50 to 250 μm, particularly preferably about 20 to 200 μm.

  The front surface (front surface) and / or the back surface of the transparent resin layer can be subjected to corona discharge treatment as necessary in order to enhance the adhesion with the adjacent layer. The method and conditions for the corona discharge treatment may follow a known method.

  In the present invention, it is desirable to form a primer layer on the front surface (front surface) and / or the back surface of the transparent resin layer. Materials for forming the primer layer include, for example, polyester resins, polyurethane resins, acrylic resins, polycarbonate resins, vinyl chloride / vinyl acetate copolymers, polyvinyl butyral resins, nitrocellulose resins, alkyl titanates, ethylene Compounds such as imines can also be used. In particular, the primer layer is preferably a two-component curable urethane resin. It is preferable to use fatty acid isocyanate (aliphatic isocyanate) such as hexamethylene diisocyanate (HMDI) as the isocyanate and acrylic polyol as the polyol, because more excellent weather resistance and adhesion can be obtained.

  The primer layer can be formed according to a known printing method, coating method or the like using these as they are or in a state dissolved or dispersed in a solvent.

Surface protective layer In the present invention, the surface protective layer is provided as the outermost surface layer. The surface protective layer may be colored as long as it is transparent. Moreover, it may be translucent as long as the pattern layer is visible. By forming the surface protective layer, the surface of the decorative sheet can be easily damaged and the stain resistance can be improved.

  In the decorative sheet of the present invention, the surface protective layer is formed of a composition containing a) an ionizing radiation polymerizable oligomer and b) a reactive silicone acrylate.

  As the ionizing radiation polymerizable oligomer, those used for known ionizing radiation curable resins can be applied. In particular, in the present invention, more specifically, (A) a urethane (meth) acrylate oligomer having at least two radically polymerizable unsaturated groups in one molecule and (B) 3 to 15 in one molecule. And an aliphatic urethane (meth) acrylate oligomer having a radically polymerizable unsaturated group.

  The urethane (meth) acrylate oligomer (A) is one having two radical polymerizable unsaturated groups in one molecule (so-called bifunctional urethane acrylate oligomer). This includes, for example, a) a diisocyanate, b) a polyhydric alcohol having two or more hydroxyl groups in one molecule (preferably a weight average molecular weight of 500 to 2000), c) a hydroxyl group at the terminal and a radically polymerizable unsaturated group. An oligomer formed by bonding a (meth) acrylate compound to be included is mentioned. The oligomer preferably has a weight average molecular weight of 1000 to 4000. If the molecular weight is less than 1000, the cured resin layer may not fully exhibit the flexibility of urethane (meth) acrylate, and the workability during bending and embossing such as V-cut processing and lapping processing is reduced. To do. On the other hand, when the molecular weight exceeds 4000, there is a possibility that characteristics such as contamination resistance may be deteriorated.

  The diisocyanate a) is an aliphatic, alicyclic or aromatic isocyanate having two or more isocyanate groups in one molecule, such as 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 1 , 6-hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like.

  Examples of the polyhydric alcohol b) include polyester polyols having a hydroxyl group at both ends, polyether polyols, polycarbonate polyols, and acrylic polyols. Examples of the polyester polyol include (a) an addition reaction product of a diol compound having an aromatic or spiro ring skeleton and a lactone compound or a derivative thereof or an epoxy compound, and (b) a condensation product of a polybasic acid and an alkylene glycol. And (c) a ring-opening polyester compound derived from a cyclic ester compound, and these can be used alone or in admixture of two or more. For example, a polyester diol having a hydroxyl group at both ends (particularly a weight average molecular weight of 500 to 2000) obtained as a condensation product with an alkylene glycol using adipic acid as the polybasic acid of (b) above has various physical properties. Therefore, it is preferably used. Examples of the polyether polyol include polytetramethylene ether glycol, polyethylene glycol, and polypropylene glycol.

  The (meth) acrylate c) is an ester compound of acrylic acid or methacrylic acid or a derivative thereof, and has a hydroxyl group at the terminal. Specifically, 2-hydroxyethyl (meth) acrylate, 2-hydroxylpropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxycyclohexyl (meth) acrylate, 5-hydroxycyclooctyl (meth) acrylate , (Meth) acrylic acid ester compounds having one polymerizable unsaturated group such as 2-hydroxy-3-phenyloxypropyl acrylate, etc., or having two or more polymerizable unsaturated groups in one molecule (meth) Examples include acrylic ester compounds.

  In the present invention, in the urethane (meth) acrylate oligomer (A), the polyhydric alcohol component is preferably a polyester polyol having a weight average molecular weight of 500 to 2000 formed from alkylene glycol and adipic acid, and the diisocyanate component is isophorone. An oligomer having a weight average molecular weight of 1000 to 3000 obtained by reacting these with diisocyanate and acrylate component as hydroxyethyl (meth) acrylate is desirable.

  The aliphatic urethane (meth) acrylate oligomer (B) has a radically polymerizable unsaturated group such as 3 to 15 (meth) acryloyl groups in one molecule. This is obtained by reacting a) an aliphatic diisocyanate, b) a polyfunctional polyol, c) a (meth) acrylate having a hydroxyl group at the terminal and having a radical polymerizable unsaturated group. ) Urethane acrylate.

  Examples of the aliphatic diisocyanate a) include 1,6-hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like.

  As the polyfunctional polyol b), those having the polyhydric alcohol as a basic skeleton and having a plurality of functional groups can be used. For example, there are a polyester polyol having a hydroxyl group at both ends, a polyether polyol, a polycarbonate polyol, and an acrylic polyol. Examples of the polyester polyol include (a) an addition reaction product of a diol compound having an aromatic or spiro ring skeleton and a lactone compound or a derivative thereof or an epoxy compound, and (b) a condensation product of a polybasic acid and an alkylene glycol. And (c) a ring-opening polyester compound derived from a cyclic ester compound. These can be used individually or in mixture of 2 or more types. Examples of the polyether polyol include polytetramethylene ether glycol, polyethylene glycol, and polypropylene glycol. Polyester diol having a weight average molecular weight of 500 to 2,000 obtained as a condensation product with alkylene glycol using adipic acid as the polybasic acid of (b) above is preferred because various physical properties are good. Used.

  The above (meth) acrylate c) is 2-hydroxyethyl (meth) acrylate, 2-hydroxylpropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxycyclohexyl (meth) acrylate, 5-hydroxycyclooctyl Examples include (meth) acrylic acid ester compounds having one polymerizable unsaturated group such as (meth) acrylate and 2-hydroxy-3-phenyloxypropyl acrylate.

  As the ionizing radiation polymerizable oligomer of the present invention, (A) urethane (meth) acrylate oligomer having at least two radical polymerizable unsaturated groups in one molecule and (B) 3 to 15 in one molecule. A mixture containing an aliphatic urethane (meth) acrylate oligomer having a radically polymerizable unsaturated group is used. In particular, as an ionizing radiation polymerizable oligomer, (A) 40 to 80% by weight of urethane (meth) acrylate oligomer having at least two radically polymerizable unsaturated groups in one molecule and (B) 3 to 15 in one molecule. A mixture composed of 60 to 20% by weight of an aliphatic urethane (meth) acrylate oligomer having one radical polymerizable unsaturated group is used. When the amount (A) is less than 40% by weight, the flexibility and malleability of the curable resin layer become insufficient, and the impact resistance may be lowered. On the other hand, when the amount (A) exceeds 70% by weight, the stain resistance may be lowered. In addition, the compounding quantity of said urethane (meth) acrylate oligomer (A) and aliphatic urethane (meth) acrylate oligomer (B) is the said oligomer (A) and oligomer in the coating composition which forms a curable resin layer. It represents the weight percent of each component relative to the total weight of (B).

  Although it does not specifically limit as reactive silicone acrylate, What reacts with the said electron beam radiation polymerizable oligomer is preferable. The silicone acrylate may be one having two or more acrylate-based polymerizable unsaturated groups in the side chain, terminal or both in one molecule. Examples of the acrylate polymerizable unsaturated group include one or more of a (meth) acryloyl group and a (meth) acryloyloxy group. However, the (meth) acryloyl group is used in the meaning of an acryloyl group or a methacryloyl group (hereinafter the same). In addition, it is preferable that the average molecular weight of silicone acrylate is 1000-100,000 normally. These reactive silicone acrylates may be known or commercially available.

  In the present invention, the silicone acrylate may be present as it is in the mixture with the electron beam curable polymerizable oligomer, but may be copolymerized with the oligomer to some extent. Such an embodiment is also included.

  The content of the reactive silicone acrylate can be appropriately determined according to the type of ionizing radiation polymerizable oligomer, etc., but is usually 5% by weight or less in the above mixture, more preferably 0.1 to 3.0% by weight, In particular, the range of 0.5 to 2.0 is more preferable.

  Any matting agent may be used as long as it can matte the surface of the surface protective layer, and any known or commercially available matting agent can be used. Examples thereof include inorganic particles such as silica and silicone resin (powder, beads); organic material powders or beads such as crosslinked alkyl, crosslinked styrene, inzoguanamine resin, urea-formaldehyde resin, phenol resin, polyethylene, and nylon. Among these, silica can be particularly preferably used. Moreover, it is preferable to use untreated silica. The wax-treated organic treated silica may bleed from the surface of the sheet when used in combination with liquid repellency, but such problems can be avoided beforehand with the untreated silica.

Further, apparent specific gravity of 0.05 to 0.4 g ^/ cm 3, it is preferable to use a silica 0.45~1.0g / cm ^3. Silica having a small apparent specific gravity is particularly preferably used as a matting agent, and silica having a large apparent specific gravity is particularly preferably used as a lubricant particle. Although there is no restriction | limiting of the addition amount, 0.05-0.4g / cm < ³ > of silica is 0.5-40 weight% normally with respect to 100 weight part of ionizing radiation-curable resins, Especially 5-30 weight% is used. It is preferable. Moreover, it is preferable that 0.45-1.0 g / cm < ³ > of silica is normally 2.5-10 weight part with respect to 100 weight part of ionizing radiation-curable resins. The silica of 0.05 to 0.4 g / cm ³ is desirably the above-described untreated silica.

  The particle size of the matting agent is not limited, and can be appropriately determined according to the use. In general, the particle size is about 0.1 to 30 μm, more preferably in the range of 3 to 6 μm.

  The composition can be prepared by mixing these components uniformly. The formation method of the surface protective layer by this composition may follow a well-known method, for example, the coating film by the said composition may be formed, and what is necessary is just to carry out crosslinking hardening of the coating film by electron beam irradiation on well-known use conditions.

  As an electron beam source of ionizing radiation, various electron beam accelerators such as a cockcroft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type are used. Preferably, what irradiates the electron with the energy of 200-300 keV can be used. Further, as the ultraviolet light source, for example, a light source such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light, a metal halide lamp may be used. In the present invention, it is desirable to previously provide a primer layer (particularly a primer layer made of urethane resin) on the transparent resin layer as a base. As the primer layer, the same layers as described above can be used.

  The surface protective layer (that is, the outermost surface of the decorative sheet) is preferably provided with an uneven pattern by embossing or the like. More preferably, a wiping process for filling the embossed concave portion with ink is performed, and the surface is coated with a two-component curable urethane resin (primer layer) and an ionizing radiation polymerizable oligomer (overcoat treatment).

  Embossing is performed to give a desired texture such as the surface of a wood board to the decorative sheet. For example, after the surface of the decorative sheet (olefin resin) is heated and softened on a heating drum, it is further heated to 160 to 180 ° C. with an infrared radiation heater, and pressed and shaped with an embossed plate provided with an uneven pattern of a desired shape. And cooled and fixed. For this, a known single wafer or rotary embossing machine may be used. Examples of the concavo-convex pattern include a wood grain conduit groove, a float pattern (a concavo-convex pattern of a raised annual ring), a hairline, a grain, a satin, and the like, and a desired pattern can be appropriately selected from these.

  The wiping process is a process of filling ink while scratching the surface with a doctor blade in a recess provided by embossing. As the wiping ink, an ink having a two-component curable acrylic urethane copolymer resin as a binder can be used. In the wiping process, the product value can be increased by expressing the design closer to the actual wood grain, particularly by performing on the wood grain conduit groove unevenness.

Adhering material The adhering material to which the decorative sheet of the present invention is applied is not limited, and the same materials as known decorative sheets can be used. For example, a wood material, a metal, ceramics, plastics, glass, etc. are mentioned. In particular, the decorative sheet of the present invention can be suitably used for a wood material. Specific examples of wood materials include veneer, wood veneer, wood plywood, particle board, medium density fiberboard (MDF) made from various materials such as cedar, firewood, firewood, pine, lawan, teak, and melapie. ) And the like.

Lamination on adherend The decorative sheet of the present invention is laminated on various adherends and used as a decorative board. The lamination method is not limited. For example, a method of sticking a decorative sheet to an adherend with an adhesive or the like can be employed. What is necessary is just to select an adhesive agent suitably from well-known adhesive agents according to the kind etc. of to-be-adhered material. Examples thereof include polyvinyl acetate, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ionomer, butadiene / acrylonitrile rubber, neoprene rubber, natural rubber and the like.

  The decorative board manufactured in this way is, for example, interior decoration materials for buildings such as walls, ceilings and floors, surface decorative boards for furniture such as window frames, doors and handrails, furniture or light electrical appliances, cabinets such as OA equipment. It can be preferably used for a surface decorative board or the like.

  The following examples illustrate the features of the present invention more clearly. However, the present invention is not limited to the scope of the examples.

Examples 1-3
A polypropylene resin film (thickness 60 μm, transmittance 10%) was prepared as a base sheet. After the front and back surfaces were subjected to corona discharge treatment, a woodgrain pattern layer was formed on the front surface by gravure printing. On the other hand, a primer layer was formed on the back surface by gravure printing.

  Next, a coating solution made of a two-component curable urethane resin was applied on the pattern layer to form an adhesive layer (thickness 3 μm). Furthermore, a transparent thermoplastic resin layer (thickness 80 μm) was formed by melt extrusion coating a polypropylene thermoplastic elastomer made of an ethylene-propylene-butene copolymer with a T-die.

  On the transparent resin layer, a two-component curable urethane resin composed of an acrylic-urethane block polymer (main agent) and hexamethylene diisocyanate (curing agent) is applied to form a primer layer (thickness 2 μm). did.

  Next, a surface protective layer was formed using a composition containing the components shown in Table 1.

  The following were used for each component in Table 1.

・ Oligomer (A): Urethane (meth) acrylate oligomer having at least two radically polymerizable unsaturated groups in one molecule ・ Oligomer (B): 3 to 15 radically polymerized / unsaturated groups in one molecule Aliphatic urethane (meth) acrylate oligomer having: Silica: average particle size 5 μm, surface untreated product (apparent specific gravity: 0.1-0.4) + average particle size 4 μm (apparent specific gravity: 0.45-0.85 )
・ Repel component (reactive silicone acrylate): Both-end reactive silicone acrylate After forming a coating film with each composition shown in Table 1, the coating film was irradiated with an electron beam under the conditions of 175 keV and 5 Mrad (50 kGy). A surface protective layer (thickness 5 μm) was formed by crosslinking and curing.

  Finally, the surface protective layer side is heated with an infrared non-contact type heater to soften the base sheet and the transparent resin layer, and then immediately embossed with heat pressure from the surface of the surface protective layer to form a wood grain conduit groove pattern A predetermined decorative sheet was obtained by shaping the uneven pattern.

Comparative Examples 1-3
A decorative sheet was prepared in the same manner as in Example 1 except that the surface protective layer was formed according to the composition shown in Table 1.

Test example 1
The following physical properties of the decorative sheets obtained in Examples and Comparative Examples were examined. The results are shown in Table 1.

(1) Flip performance (initial)
Using thick magic ink (Yuki Uchida oil-based ink), the repellency characteristics when writing on the surface protective layer of the decorative sheet were confirmed. The state where ink was repelled, that is, the ink was in the form of droplets, was evaluated as “◯”, and the ink was not repelled.

(2) Repelling performance (color after wiping off)
After the handwriting written in (1) was wiped off with a waste cloth, the residual color was observed. The state where it was completely wiped off was evaluated as “◯”, and the state where the ink was not wiped off and the same state as before the wiping was maintained was evaluated as “x”. The results are shown in Table 1.

(3) Repel performance (eraser)
The surface protective layer surface of the decorative sheet was rubbed 10 times with an eraser, and then the test of (2) was performed on the surface. The state where it was completely wiped was evaluated as “◯”, and the state where the ink was not wiped off and the same state as before the wiping was maintained was evaluated as “x”. The results are shown in Table 1.

(4) Repelling performance (after S-UV test)
The decorative sheet was tested according to JIS-B-7350 as an accelerated weather resistance test. Using a sunshine carbon arc lamp type weather resistance tester, a black panel temperature of 63 ° C., an irradiation amount of 25.5 mW / cm ² (365 nm), and a rainfall time of 18 minutes in 120 minutes of irradiation were conducted for a total of 200 hours. After the test, the above test (2) was performed on the surface. The state where it was completely wiped off was evaluated as “◯”, and the state where the ink was not wiped off and maintained the same state as before the wiping was evaluated as “x”. The results are shown in Table 1.

  From the above results, it can be seen that the decorative sheet of the present invention has excellent repellency (contamination resistance) and durability.

Claims (9)

A decorative sheet for use by laminating on an adherend,
(1) The sheet has at least a base sheet, a pattern layer, a transparent resin layer, and a surface protective layer in order,
(2) The surface protective layer is formed of a composition comprising a) an ionizing radiation polymerizable oligomer and b) a both-end reactive silicone acrylate,
(3) The ionizing radiation polymerizable oligomer includes (A) 40 to 80% by weight of urethane (meth) acrylate oligomer having two radical polymerizable unsaturated groups in one molecule and (B) 3 to 3 in one molecule. It is a mixture comprising 60 to 20% by weight of an aliphatic urethane (meth) acrylate oligomer having 15 radically polymerizable unsaturated groups.
A decorative sheet characterized by that. The decorative sheet according to claim 1, wherein at least a primer layer is formed between the transparent resin layer and the surface protective layer. The decorative sheet according to claim 1 or 2, wherein the surface protective layer contains a matting agent. The decorative sheet according to claim 3, wherein a part or all of the matting agent is silica particles. The decorative sheet according to claim 3 or 4, wherein the matting agent contains untreated silica particles. The decorative sheet according to any one of claims 3 to 5, wherein silica having an apparent specific gravity of 0.05 to 0.4 g / cm ³ or 0.45 to 1.0 g / cm ³ is used in combination as the matting agent. The decorative sheet according to any one of claims 1 to 6, wherein the surface protective layer has irregularities formed by embossing. The decorative sheet according to any one of claims 1 to 7, wherein at least one of the transparent resin layer and the base sheet is a polyolefin resin. A decorative board obtained by laminating a sheet on an adherend so that the surface protective layer of the decorative sheet according to any one of claims 1 to 8 becomes an outermost surface layer.